特朗普对言论自由的“战争”所产生的寒蝉效应，远远超出了校园的围墙——这才是关键。

Younger Americans have soured on the second Donald Trump presidency, but they are not protesting it.

Despite an unpopular Iran war and an even more unpopular Trump administration, college campus protests nationwide have gone silent. And at many schools, student activism is virtually nonexistent.

This silence comes in the wake of a relentless Trump administration war on campus speech that has involved lawsuits, arrests, deportations and expulsions.

Reports cite a range of complicated factors for the restraint, from apathy to technology-induced incapacity. But as public policy and law and social science experts, we believe students aren’t protesting for a very simple reason: They are afraid. They are self-censoring and disengaging from campaign activism to avoid punitive measures.

In law and social science, we call this impact a chilling effect – the behavioral tendency for people in face of a threat to self-censor and restrain their activities for self-protection.

It’s increasingly clear to us that these impacts are not incidental or ancillary to Trump administration policy. Rather, the chilling effects are the point. This is the closest thing to a consistent governing strategy in Trump’s second term.

The broader chill of Trump threats

Chilling effects can be subtle, but today they are everywhere. And it’s not just students who are chilled by Trump administration threats.

Professors are censoring themselves in lectures and rewriting syllabuses. Researchers are stripping grant applications of words that might attract federal scrutiny, or abandoning the topics entirely. Media outlets are modifying their news coverage to avoid Trump lawsuits or sanctions.

Law enforcement and regulatory agencies are refusing to investigate Trump-aligned actors inside or outside government, and major national law firms are declining cases challenging Trump administration policies.

Publishers are “stepping back” from LGBTQ+ books and other progressive subjects. Many in targeted immigrant communities are afraid to leave home to go to work or school.

In most cases, these people and institutions are not being specifically targeted or threatened by Trump. But they are afraid, and their fear is doing the administration’s work for it. They stay silent, avoid attention and confrontation, and look the other way. In other cases, they change their speech and behavior to accommodate or conform to the administration’s worldview.

Of course, there are counterexamples, such as the winter protests in Minneapolis in response to brutality by agents with U.S. Immigration and Customs Enforcement, and the recent “No Kings” rallies. But even here, the broader but less visible trend – chilling effects – is evident.

For instance, in recent reporting on the latest No Kings rallies, many media outlets observed that students were noticeably missing, despite the Trump administration’s unpopularity among younger Americans.

A persistent strategy

We believe none of this is by accident.

In a new book, “Chilling Effects: Repression, Conformity, and Power in the Digital Age,” one of us – Jon Penney – explains how law, technology, and state and corporate power are weaponized to chill and repress, and the dangers this poses for the United States and other democratic societies. The other – Bruce Schneier – has extensively studied the security infrastructure enabling this.

What we see isn’t gratuitous government cruelty, chaos or vengeance. Instead, we see a persistent strategy to maximize fear and chilling effects in ways that are corrosive to freedom and democracy.

Research suggests that surveillance, personal threats, uncertainty and abuse of power are key factors in doing so. The federal government has a clear and systematic pattern of employing these very mechanisms across a number of domains far beyond campuses.

They are evident in militarized raids by Immigration and Customs Enforcement and in journalists being arrested and indicted for reporting on protests. They are made clear in the long list of political enemies the Trump administration has investigated or threatened, including the Federal Reserve chairman. And they can also be seen in the weaponization of technology, including ramping up surveillance to target critics and protestors.

Corrosive to freedom and democracy

History offers some guidance on impacts.

During the McCarthy era, overreaching laws, surveillance, and public and private sector reprisals ostensibly targeted alleged communists. But the real aim was often to suppress progressive journalists, trade unions and political opposition.

In the 1960s, these same tactics were reused by Southern states to chill the Civil Rights Movement. Historians have written about how the widespread fear and conformity of these periods reshaped American society in enduring ways, including the destruction of progressive political movements and both delaying and muting the Civil Rights Movement itself.

When such state threats are systematized, they can foment a broader climate of fear, self-censorship and conformity. In that climate, dissenting speech, political opposition, democratic mobilization and other checks on power become increasingly difficult, even dangerous. It is no surprise, for instance, that Trump critics regularly admit to self-censorship, fearing for their safety.

Chilling effects are thus not only repressive – causing self-censorship – but productive. They produce conforming and compliant speech and behavior, which can have longer-term social impacts. They not only undermine protected rights and suppress accountability but can promote social change – even without a popular mandate to do so.

This latter point is often missed. It explains Trump’s assaults on universities and cultural institutions such as the Kennedy Center for the Arts and the Smithsonian. Often dismissed as peculiar Trump obsessions, they are fully consistent with Project 2025 – the sweeping policy blueprint for Trump’s second term authored by a coalition of conservative groups and its call to target the “institutions of American civil society” and “wield federal power” to “reverse” decades of progressive cultural advancements.

In the near term, this means an increasingly weakened democratic society, with the government and its patrons enjoying freedom to pursue their objectives. Over the long term, this can mean a changed society as more conformist and compliant speech and culture become more widely accepted and entrenched.

Not inevitable

In our view, this future is not inevitable, just as the McCarthy era “Red Scare” and violent civil rights era repression were not. In both cases, fear and chilling effects were resisted in law and civil society, as they can be today.

But the central mechanisms – surveillance, uncertainty, personal threats and abuse of power – would need to be addressed. For instance, new legislation could ensure justice for lawless government actors and constrain surveillance. Courts can block abuses of federal power, including illegal arrests, detentions and mass citizen databases.

The media, lawyers and civil society can hold the government accountable. And students, teachers, universities and cultural institutions can resist the tendency to self-censor and conform.

The citizen mobilization in Minnesota and the No Kings rallies are examples of that. But to resist chilling effects and their dangers over the long term, this would have to be the norm, not the exception.

Jon Penney has acted as an expert witness, on a pro bono basis, for the American Civil Liberties Association in litigation challenging the legality of government surveillance.

Bruce Schneier does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.